A one-time U.S. visa chief in Vietnam has pleaded guilty to bribery and other charges for accepting more than $3 million in bribes to hand out visas for entry into the United States.

The U.S. Foreign Service officer, Michael Sestak, admitted the scheme Wednesday in a federal court in Washington. He acknowledged that he took bribes to approve nearly 500 visas while serving in Ho Chi Minh City from 2010 to last year.

Prosecutors said Sestak conspired with four other people -- two Americans living in Vietnam and two Vietnamese citizens - to collect nearly $10 million in bribes that ranged from $15,000 to $70,000. American officials said the 42-year-old Sestak used his $3 million share of the bribes to buy nine pieces of real estate in Thailand, all of which he is forfeiting as part of his guilty plea agreement.

Sestak has yet to be sentenced, but U.S. guidelines call for a prison term of about 19 to 24 years.